FIV is a commonly diagnosed disease in NZ. It is thought that along with Australia, we have one of the highest rates in the world, due to a high cat population per capita, our cats living an indoor/outdoor lifestyle and a large population of feral cats living in a mild climate.
FIV is transmitted through saliva, with the majority of infections resulting from cat bites. Once infected, the cat remains infected for life. After contracting the disease, cats may show no symptoms for many years. However during this time, the immune system slowly deteriorates and eventually leads to cat AIDS, where the immune system becomes too weak to fight off other infections or diseases. Sadly, there is no cure for the FIV infection.
The prevalence in NZ is unknown, but it is thought that around 15% of all pet cats and up to 30% of feral cats have FIV! This varies between regions and unfortunately the prevalence of FIV in the Bay of Plenty is not known.
The good news is that Feline FIV and feline AIDs cannot be transmitted to people – it is species specific.
There are 5 known sub-types of FIV: A, B, C, D & E. In NZ, we mostly have subtypes A and C, with the bigger proportion being subtype C. There is a vaccine available to prevent FIV infection, however it was developed overseas and is for subtype A and D. It is thought that the vaccine gives protection for other subtypes, and this has been shown to be the case in Australia & Canada. However it hasn’t been studied in NZ on NZ subtypes, and so the level of protection offered is unknown. The vaccine company says 60% of cats given Fel-O-Vax FIV vaccine will be protected, but individual studies suggest it could be anywhere between 0 – 100%. The Fel-O-Vax FIV vaccine’s effectiveness in NZ therefore continues to be debated within the veterinary and pharmaceutical community.
A study is currently underway at Massey University on NZ FIV-vaccinated cats, aiming to show the level of protection provided by the vaccine against the NZ strains of FIV.
An FIV vaccination course involves 3 vaccinations, 2-4 weeks apart and then a yearly booster vaccination. These can be given at the same time as the core vaccinations.
There is no cure for FIV – although not proven to work on NZ FIV subtypes, FIV vaccination is a cats only possible protection (other than being kept indoors or isolated from other cats).
As the in-house FIV test cannot distinguish between a cat that is vaccinated for FIV and a cat that has the FIV infection, cats require a blood test before they are vaccinated, to ensure they don’t already have the FIV infection.
It is also recommended that cats which are vaccinated for FIV are microchipped and put on the national database, so that if they ever went missing or were rehomed, their positive FIV test result could be determined to be due to vaccination, not the FIV disease.
We are currently encouraging testing of our feline patients to ensure optimal health care for those patients that have contracted the disease, to help prevent its spread and to build up a picture of how common the disease is in our area.
Nina Smith: BVSc